<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h2>file upload</h2>
    <form th:action="@{/file}" method="post" enctype="multipart/form-data">
        username<input type="text" name="username"><br/>
        email<input type="email" name="email"><br/>
        avatar<input type="file" name="avatar"><br/>
        photos<input type="file" name="photos" multiple>
        <input type="submit" value="submit">
    </form>
</body>
</html>